Tiêu đề 11. ALCOHOLS, PHENOLS AND ETHERS.pdf ✅

METHODS OF PREPARATION OF ALCOHOLS FROM HYDROBORATION OXIDATION From alkenes, by acid Catalysed Hydration: Reduction of Aldehyde, Ketone and Carboxylic Acid C C C H OH + H2 O C H+   OH eg. CH3 -CH=CH2 + H2 O CH3 -CH-CH3 H+   CH3 -CH=CH2 +(H-BH2 ) 2 CH3 -CH-CH2 (CH3 -CH2 -CH2 ) (CH 2 BH 3 -CH2 -CH2 ) 3 B 3CH3 -CH2 -CH2 -OH+B(OH)3 CH3 -CH=CH2 CH3 -CH=CH2 Propan-l-ol H BH2 CH3 -CH=CH2 pd 2 2 R CHO H R CH OH − + → − NaBH4 RCOR R CH R → − −′ OH 4 2 (i) LiAlH (ii) H O 2 RCOOH R CH OH → − − From Grignard reagent C O + R + MgX C R OH C H2 O O Mg Mg(OH)x + X δ− +δ PHYSICAL PROPERTIES M.P. and B.P. ∝ Molecular mass M.P. and B.P. ∝ Soluble in water due to H-bonding Colorless with characteristic s smell CHEMICAL PROPERTIES Reaction involving cleavage of -OH bond. Acidity: Due to the presence of polar-OH group. Oxidation Esterification H + NaOH + H2 O OH ONa R CH2 OH > > 1° alcohol R R R R R OHCCH-OH 2° alcohol Dehydration Reaction O C OHH C C + H2 O H Heat + → Oxidation [O] 2 Aldehyde Carboxylic Acid R CH OH R C O R C OH − → − = → − − H 2 H 2 Pyridine R OH R COOH ROCOR H O R OH (R CO) O ROCOR R COOH R OH R COCl ROCOR HCl + + − + ′ ′ + − + ′ ′ + ′ − + ′ ′ +       CHEMICAL TEST FOR ALCOHOL Primary Alcohol 1) P+I2 2 2) AgNO 3) HNO , KOH R CH OH Red Colours − − → Secondary Alcohol Tertiary Alcohol 2 2 2) AgNO 3) HNO , KOH R CH OH Blue Colours 2 1) P I + − → 2 1) P I KOH 3 2) AgNO 3) HNO R C OH NoReaction No Colours + − → → ALCOHOLS FROM DIAZONIUM SALTS FROM BENZENE SUPLHONIC ACID NH2 Aniline Benzene Diazonium salt NaNO2 HCl H2 O Warm N ≡ NCL + N2 + HCl OH Oleum (i) NaOH (ii) H+ SO3 H OH FROM CUMENE: DOW'S PROCESS: METHODS OF PREPARATION OF PHENOL OH + CH3 COCH3 O3 H+ H2 O C–O–OH CH CH3 CH3 CH3 CH3 Cumene Cumen Hydroperoxide (i) 623 K, 300 atm (ii ) HCl Chlorobenzene NaOH Phenol + → PHENOL CHEMICAL PROPERTIES PHYSICAL PROPERTIES Colorless crystalline solid or Liquid Higher boiling point due to Hydrogen Bonding Nitration OH NO2 2,4,6-Trinitro-phenol NO NO2 2 OH Conc. NO2 HNO3 Halogeneation Electrophilic Aromatic substitution OH Br Br + 3HBr Br OH + 3Br2 Structure R-OH where R = alkyl group Structure R-O-R′ where R and R′ can be same or different alkyl group Victor Mayer Test Oxidation Phenol OH Na2 Cr2 O7 H2 SO4 OH O O Benzoquinone By Dehydration of Alcohols H SO 2 4 3 2 2 5 2 5 413 K 2CH CH OH C H O C H − − → − − CLEAVAGE OF C-O BOND + H-X + R-X OR OH R O R HX R X ROH R O R HX R X R OH − − + → − + − − ′ + → − + ′ For Tertiary Group: CH3 - C - OCH3 + HI → CH3 OH + CH3 - C - I CH3 CH3 CH3 CH3 Reimer-Tiemann reaction: Treatement of phenol with CHCl3 + KOH Intermediate Salicyaldehyde NaOH CHCl2 CHCl3 + Aq. NaOH OH H OH + CHO O Na+ - O Na - CHO CHEMICAL PROPERTIES (I) HALOGENATION PREPARATION OF ETHER (II) FRIEDEL-CRAFTS REACTION + CH3 Cl AlCl3 OCH3 CH3 OCH3 H3 CO H3 C + ELECTROPHILIC SUBSTITUTION Williamson Synthesis R X R O Na R O R NaX − + − − → − − + :: :: – + ETHER + Br Br OCH3 OCH3 Br2 in Ethanoic Acid OCH3 ALCOHOL, PHENOL AND ETHER